Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion with Endoscopic Disc Drilling Preparation Technique for Symptomatic Foraminal Stenosis Secondary to Severe Collapsed Disc Space: A Clinical and Computer Tomographic Study with Technical Note

Comparative clinical efficacy of percutaneous coaxial large-channel endoscopic lumbar interbody fusion and transforaminal lumbar interbody fusion for degenerative lumbar spinal stenosis: a retrospective study

This study aimed to evaluate the clinical efficacy of percutaneous coaxial large-channel endoscopic lumbar interbody fusion (PCLE-LIF) and transforaminal lumbar interbody fusion (TLIF) in the treatment of degenerative lumbar spinal stenosis. The clinical data of patients with degenerative lumbar spinal stenosis who underwent PCLE-LIF (experimental group) and TLIF (control group) surgery from September 2019 to September 2021 were retrospectively analyzed. We collected clinical data and compared the two groups in terms of perioperative parameters, treatment response rate, inflammatory response markers, postoperative complications, postoperative pain, and functional recovery. The results showed that the treatment outcomes in the experimental group were significantly better than those in the control group. Specifically, perioperative parameters and inflammatory response markers in the experimental group were significantly better than those in the control group, with statistically significant differences (P < 0.05). The overall treatment response rate in the experimental group was significantly higher than that in the control group (P < 0.05). Meanwhile, the incidence of postoperative complications in the experimental group was lower than that in the control group, postoperative VAS pain scores and ODI functional scores were lower, and postoperative JOA functional scores were higher than those in the control group, with statistically significant differences (P < 0.05). In conclusion, PCLE-LIF appears to be a promising technique with better clinical outcomes in the treatment of degenerative lumbar spinal stenosis.

Optimizing Disc and Cartilage Endplate Preparation in Full-Endoscopic Lumbar Interbody Fusion: An In-Depth Exploration of Surgical Instruments with a Technique Note and Narrative Review

Full-endoscopic lumbar interbody fusion (FELIF) is a critical yet challenging procedure. However, extensive analyses of discectomy and cartilage endplate preparation techniques are limited. This can be attributed to the lack of universal protocols owing to diverse surgical practices and equipment preferences. Therefore, this narrative review presents a comprehensive overview of discectomy and cartilage endplate preparation techniques in FELIF. A literature search of the PubMed, Embase, and Google Scholar databases in December 2023 retrieved 490 studies, of which 53 met the predefined inclusion criteria, and 1373 patients were included in the analyses. Spinal endoscopic disc and cartilage endplate removal can be categorized into 2 main types: removal under direct endoscopic visualization and removal under radiographic guidance with the protection of a working sheath following the endoscope's removal. Removal under direct visualization ensures the safety and precision of the procedure. Radiographic guidance can enhance the efficiency of the removal process. Specially designed instruments can be utilized through the narrow working channels of spinal endoscopes for the scraping surgery. Moreover, many traditional spinal endoscopic instruments, through specific techniques and manipulations, can also aid in cartilage removal. The approaches and techniques vary significantly among physicians, but overall, these instruments and techniques aim to achieve a safe and efficient disc-scraping outcome. Thus, this review may offer a comprehensive guidance to surgeons in selecting the most efficient practices for FELIF. Uniform procedural protocols are needed to ensure broader adoption and standardized practice.

Transforaminal posterior lumbar interbody fusion microscopic safe operating area: a three-dimensional model study based on computed tomography imaging

BACKGROUND

Endoscopic spine lumbar interbody fusion (Endo-LIF) is well-regarded within the academic community. However, it presents challenges such as intraoperative disorientation, high rates of nerve damage, a steep learning curve, and prolonged surgical times, often occurring during the creation of the operative channel. Furthermore, the undefined safe operational zones under endoscopy continue to pose risks to surgical safety. We aimed to analyse the anatomical data of Kambin's triangle via CT imaging to define the parameters of the safe operating area for transforaminal posterior lumbar interbody fusion (TPLIF), providing crucial insights for clinical practice.

METHODS

We selected the L4-L5 intervertebral space. Using three-dimensional (3D), we identified Kambin's triangle and the endocircle within it, and recorded the position of point 'J' on the adjacent facet joint as the centre 'O' of the circle shifts by angle 'β.' The diameter of the inscribed circle 'd,' the abduction angle 'β,' and the distances 'L1' and 'L2' were measured from the trephine's edge to the exiting and traversing nerve roots, respectively.

RESULTS

Using a trephine with a diameter of 8 mm in TPLIF has a significant safety distance. The safe operating area under the TPLIF microscope was also clarified.

CONCLUSIONS

Through CT imaging research, combined with 3D simulation, we identified the anatomical data of the L4-L5 segment Kambin's triangle, to clarify the safe operation area under TPLIF. We propose a simple and easy positioning method and provide a novel surgical technique to establish working channels faster and reduce nerve damage rates. At the same time, according to this method, the Kambin's triangle anatomical data of the patient's lumbar spine diseased segments can be measured through CT 3D reconstruction of the lumbar spine, and individualised preoperative design can be conducted to select the appropriate specifications of visible trephine and supporting tools. This may effectively reduce the learning curve, shorten the time operation time, and improve surgical safety.

Comparison of Outcomes Between Endoscopic Transforaminal Lumbar Interbody Fusion and Minimally Invasive Transforaminal Lumbar Interbody Fusion in Patients With Single-Level Lumbar Degenerative Disease: A Retrospective Study

OBJECTIVE

The objective of this study was to compare the clinical and radiological outcomes of endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

METHODS

This retrospective study included 110 patients with single-level lumbar degenerative disease who underwent Endo-TLIF or MIS-TLIF between January 2019 and December 2021. Patients were divided into Endo-TLIF (n = 55) and MIS-TLIF groups (n = 55). Perioperative, clinical, and radiological outcomes were assessed.

RESULTS

The Endo-TLIF group had significantly lower blood loss and shorter hospital stay. However, the operation time was significantly longer and there was more x-ray exposure than in the MIS-TLIF group. There were no significant differences in complications between the groups. The Endo-TLIF group showed significantly lower creatine kinase levels than the MIS-TLIF group at 3 days postoperatively (P < 0.05), but not at 7 days postoperatively (P > 0.05). Oswestry Disability Index and visual analog scale scores were significantly reduced in both groups at different time points postoperation compared to preoperation. The visual analog scale score in the Endo-TLIF group was lower than that in the MIS-TLIF group at 3 days postoperatively. Moreover, no significant differences were found in fusion rates, lumbar lordosis, and lumbar segmental lordosis between the 2 groups (P > 0.05).

CONCLUSIONS

Endo-TLIF might be considered as an effective and reliable treatment option for single-level lumbar degeneration. It results in less trauma and faster postoperative recovery, but a longer operative time and more x-ray exposure than MIS-TLIF. Endo-TLIF has effects on clinical and radiological outcomes that are comparable to those of MIS-TLIF.

The novel Kambin Torpedo full-endoscopic lumbar interbody fusion technique: a case series

PURPOSE

Full-endoscopic lumbar interbody fusion (FELIF) is a new-generation treatment for spondylolisthesis. However, owing to their unique characteristics, the two main endoscopic fusion trajectories, the trans-Kambin and posterolateral approaches, have important limitations. Herein, we aimed to introduce a new technique called Kambin Torpedo FELIF (KT-FELIF).

METHODS

The KT-FELIF technique is based on the trans-Kambin approach. It additionally completes ipsilateral total facetectomy and contralateral direct decompression. Thus, this novel technique combines the advantages of the trans-Kambin and posterolateral approaches.

RESULTS

We reported on the indications and technical steps of KT-FELIF and provided intraoperative and animated videos to clarify the procedure. Short-term follow-up based on 3-month postoperative computed tomography and plain films images taken at least 3 months after surgery showed adequate bony decompression, a large bone graft contact area, and good intervertebral trabecular bone growth without radiolucent lines between the graft, cage, and end plate. The clinical results, such as ipsilateral and contralateral visual analog scale and Oswestry disability index values, gradually improved at 1 and 3 months postoperatively. No complications were observed.

CONCLUSIONS

KT-FELIF is a promising FELIF technique for achieving bilateral direct decompression through a unilateral approach while accomplishing thorough discectomy and endplate preparation.

The Endoscopic Lumbar Interbody Fusion: A Narrative Review, and Future Perspective

Lumbar interbody fusion stands as a preferred surgical solution for degenerative lumbar spine diseases. The procedure primarily aims to establish lumbar segment stability, directly addressing patient symptoms associated with spinal complications. Traditional open surgery, though effective, is linked with notable morbidities and extended recovery time. To mitigate these concerns, minimally invasive surgery (MIS) has garnered significant popularity, presenting an appealing alternative with numerous benefits such as reduced soft tissue trauma, decreased blood loss, and expedited recovery. Among MIS procedures, full endoscopic spinal surgery, characterized by its minimal invasiveness, holds the potential to further minimize morbidities while enhancing surgical outcomes. Endoscopic lumbar interbody fusion, a novel procedure within this paradigm, has gained attention for offering advantages comparable to those of minimally invasive transforaminal lumbar interbody fusion. However, the safety, efficacy, and associated surgical techniques and instrument design of this method continue to be subjects of ongoing debate. This paper critically reviews current evidence on the safety, efficacy, and advantages of endoscopic lumbar spinal interbody fusion, examining whether it could indeed supersede existing mainstream techniques.

The Role and Future of Endoscopic Spine Surgery: A Narrative Review

Many types of surgeries are changing from conventional to minimally invasive techniques. Techniques in spine surgery have also changed, with endoscopic spine surgery (ESS) becoming a major surgical technique. Although ESS has advantages such as less soft tissue dissection and normal structure damage, reduced blood loss, less epidural scarring, reduced hospital stay, and earlier functional recovery, it is not possible to replace all spine surgery techniques with ESS. ESS was first used for discectomy in the lumbar spine, but the range of ESS has expanded to cover the entire spine, including the cervical and thoracic spine. With improvements in ESS instruments (optics, endoscope, endoscopic drill and shaver, irrigation pump, and multiportal endoscopic), limitations of ESS have gradually decreased, and it is possible to apply ESS to more spine pathologies. ESS currently incorporates new technologies, such as navigation, augmented and virtual reality, robotics, and 3-dimentional and ultraresolution visualization, to innovate and improve outcomes. In this article, we review the history and current status of ESS, and discuss future goals and possibilities for ESS through comparisons with conventional surgical techniques.

Spinal Canal Remodeling and Indirect Decompression of Contralateral Foraminal Stenosis After Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion

Objective: There is a lack of literature on indirect decompression in uniportal endoscopic posterolateral transforaminal lumbar interbody fusion (EPTLIF). Our aim is to evaluate the dimensions of the spinal canal and contralateral foramen before and after EPTLIF.Methods: This is a retrospective study of patients who underwent EPTLIF in a tertiary spine centre over a 2-year period. The cross-sectional area of the spinal canal and the contralateral foramen at the level of fusion were measured on magnetic resonance imaging scan at 1-day postoperation and at the final follow-up. Patients were grouped according to the decompression performed as per the clinician’s judgement.Results: One hundred fifty-two levels of fusion were performed in 120 patients. There was a statistically significant clinical improvement in visual analogue scale and Oswestry Disability Index scores postoperation. The measurements of the spinal canal area were 106.0 mm², 138.8 mm², and 195.5 mm²; while contralateral foraminal area were 73.2 mm², 104.4 mm², and 120.7 mm² at preoperation, 1-day postoperation, and at the final follow-up, respectively (p < 0.001). For the subgroup analyses, spinal canal area measurements for the bilateral decompression cohort (n = 35) were 57.0 mm², 123.9 mm², and 191.8 mm²; for the ipsilateral decompression cohort (n = 42) were 89.3 mm², 128.9 mm², 183.3 mm²; and for the cohort without any decompression and only cage inserted (n = 75) were 138.3 mm², 151.2 mm², and 204.1 mm² (p < 0.001). Contralateral foraminal area measurements were 73.3 mm², 106.4 mm² and 120.4 mm² in the bilateral decompression cohort; 69.5 mm², 99.0 mm², 116.9 mm² in the ipsilateral decompression cohort; and 75.1 mm², 106.5 mm², 122.9 mm² in the cohort without any decompression (p < 0.001).Conclusion: Indirect decompression of both the spinal canal and the contralateral foramen can be achieved via EPTLIF. Decompression on an asymptomatic contralateral side is not necessary.

Retrospective Case Control Study: Clinical and Computer Tomographic Fusion and Subsidence Evaluation for Single Level Uniportal Endoscopic Posterolateral Approach Transforaminal Lumbar Interbody Fusion Versus Microscopic Minimally Invasive Transforaminal Interbody Fusion

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

Assessment of difference in clinical and computer tomographic outcomes between the 2 cohorts.

METHODS

Computer tomographic evaluation by Bridwell's grade, Kim's stage, Kim's subsidence grade and clinical evaluation by VAS, ODI and McNab's criteria on both cohorts.

RESULTS

33 levels of Endo-TLIF and 22 levels of TLIF were included, with a mean follow up of 14.3 (10-24) and 22.9 (13-30) months respectively. Both Endo-TLIF and TLIF achieved significant improvement of pain and ODI at post-operative 4 week, 3 months and at final follow up with VAS 4.39 ± 0.92, 5.27 ± 1.16 and 5.73 ± 1.21in Endo-TLIF and 4.55 ± 1.16, 5.05 ± 1.11 and 5.50 ± 1.20 in TLIF respectively and ODI at post-operative 1 week, 3 months and final follow up were 43.15 ± 6.57, 49.27 ± 8.24 and 51.73 ± 9.09 in Endo-TLIF and 41.73 ± 7.98, 46.18± 8.46 and 49.09 ± 8.98 in TLIF respectively, P < 0.05. Compared to TLIF, Endo-TLIF achieved better VAS with 0.727 ± 0.235 at 3 months and 0.727 ± 0.252 at final follow up and better ODI with 3.88 ± 1.50 at 3months and 3.42 ± 1.63 at final follow up, P < 0.05. At 6 months radiological evaluation comparison of the Endo-TLIF and TLIF showed significant with more favorable fusion rate in Endo-TLIF of -0.61 ± 0.12 at 6 months and -0.49 ± 0.12 at 1 year in Bridwell's grading and 0.70 ± 0.15 at 6 months and 0.56 ± 0.14 at 1 year in Kim's stage.There is less subsidence of 0.606 ± 0.18 at 6 months and -0.561 ± 0.20 at 1 year of Kim's subsidence grade, P < 0.05.

CONCLUSION

Application of single level uniportal endoscopic posterolateral lumbar interbody fusion achieved better clinical outcomes and fusion rate with less subsidence than microscopic minimally invasive transforaminal lumbar interbody fusion in mid-term evaluation for our cohorts of patients.

Remodeling of Epidural Fluid Hematoma after Uniportal Lumbar Endoscopic Unilateral Laminotomy with Bilateral Decompression: Comparative Clinical and Radiological Outcomes with a Minimum Follow-up of 2 Years

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To evaluate the clinical and radiological effects of epidural fluid hematoma in the medium term after lumbar endoscopic decompression.

OVERVIEW OF LITERATURE

There is limited literature comparing the effect of postoperative epidural fluid hematoma after uniportal endoscopic decompression.

METHODS

Magnetic resonance imaging (MRI) and clinical evaluation were performed for patients with single-level uniportal endoscopic lumbar decompression with a minimum follow-up of 2 years.

RESULTS

A total of 126 patients were recruited with a minimum follow-up of 26 months. The incidence of epidural fluid hematoma was 27%. Postoperative MRI revealed a significant improvement in the postoperative dura sac area at postoperative day 1 and at the upper endplate at 6 months in the hematoma cohort (39.69±15.72 and 26.89±16.58 mm2) as compared with the nonhematoma cohort (48.92±21.36 and 35.1±20.44 mm2), respectively (p <0.05); and at the lower endplate on postoperative 1 day in the hematoma cohort (51.18±24.69 mm2) compared to the nonhematoma cohort (63.91±27.92 mm2) (p <0.05). No significant difference was observed in the dura sac area at postoperative 1 year in both cohorts. The hematoma cohort had statistically significant higher postoperative 1-week Visual Analog Scale (VAS; 3.32±0.68) pain and Oswestry Disability Index (ODI; 32.65±5.56) scores than the nonhematoma cohort (2.99±0.50 and 30.02±4.84, respectively; p <0.05). No significant difference was found at the final follow-up VAS, ODI, and MRI dura sac area.

CONCLUSIONS

Epidural fluid hematoma is a common early postoperative MRI finding in lumbar endoscopic unilateral laminotomy with bilateral decompression. Conservative management is the preferred treatment option for patients who do not have a neurological deficit. Symptoms last only a few days and are self-limiting. A common endpoint is a remodeled fluid hematoma and the subsequent expansion of the dura sac area.

Analysis of curative effect of percutaneous coaxial large channel endoscopic lumbar interbody fusion in the treatment of degenerative lumbar spinal stenosis

Objective

To investigate the clinical efficacy and technical points of Percutaneous Coaxial Large-channel Endoscopic Lumbar Interbody Fusion (PCLE-LIF) in the treatment of degenerative lumbar spinal stenosis.

Methods

The clinical data of patients with single-segment degenerative lumbar spinal stenosis who underwent PCLE-LIF surgery from January 2019 to June 2021 were retrospectively analyzed. Surgery-related data included symptom duration, operation time, hospital stay, and complication rate. Functional score data included low back pain and lower extremity pain VAS score, ODI score, and MacNab criteria were used to evaluate clinical effects. The Brantigan criteria were used to evaluate the interbody fusion.

Results

There were 62 patients in this group, including 35 males and 27 females. The surgical sites were all lower lumbar spine, including 35 cases of lumbar L4/5 and 27 cases of L5/S1. The length of hospital stay was 7.7 ± 1.4 days. All patients were followed up regularly for 1 year. The interbody fusion rate was 93.5% at 1 year after operation. There were 2 cases of numbness, 2 cases of nerve edema and pain, 1 case of cage displacement, and 1 case of pedicle screw loosening. The complication rate was 9.6%. The VAS scores of low back pain 1 day before surgery, 3 days, 3 months and 1 year after surgery were 4.48 ± 1.06, 0.84 ± 0.81, 0.40 ± 0.56, 0.39 ± 0.69, and the VAS of lower extremity pain at each time point of appeal were 5.58 ± 0.98, 0.91 ± 0.58, 0.31 ± 0.46, 0.19 ± 0.40. The ODI scores at 1 day before surgery, 3 months and 1 year after surgery were 60.01 ± 6.21, 15.58 ± 2.84, 8.82 ± 2.15. The ODI scores and VAS scores of low back pain and lower extremity pain at each follow-up time point after operation were significantly lower than those before operation (p < 0.05). The 1-year follow-up after operation was evaluated by the modified MacNab standard, and the results were excellent in 36 cases, good in 23 cases, fair in 3 cases, and poor in 0 cases, with an excellent and good rate of 95.2%.

Conclusion

Percutaneous coaxial large-channel endoscopic lumbar interbody fusion in the treatment of degenerative lumbar spinal stenosis has good short-term efficacy and high safety, and is worthy of popularization.

Full-Endoscopic Lumbar Interbody Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion with a Tubular Retractor System: A Retrospective Controlled Study

OBJECTIVE

The objective of this study was to compare the safety and clinical efficacy of full-endoscopic lumbar interbody fusion (FE-LIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

METHODS

A total of 70 patients with single-level lumbar degenerative diseases underwent FE-LIF or MIS-TLIF with a tubular retractor system from August 2018 to August 2020. Postoperatively, the efficacy and safety were compared using several clinical and radiological indices.

RESULTS

A total of 32 patients underwent FE-LIF and 38 received MIS-TLIF with a tubular retractor system, and all patients had no apparent complications. The FE-LIF group had higher radiation exposure, longer operation time, and less bleeding than the MIS-TLIF group (P < 0.05). Postoperative lumbar magnetic resonance imaging showed that the nerve decompression was sufficient. The pain in the lower back and legs was significantly relieved, and the Oswestry Disability Index (ODI) score was greatly improved after surgery (P < 0.01) in both the groups. The sensory and motor functions of nerve roots were remarkably recovered in both the groups at the 1-year follow-up (P < 0.05), and there was no significant difference in MacNab scores between the 2 groups. As per Mannion's fusion classification, the interbody fusion rate was significantly better in the FE-LIF group than in the MIS-TLIF group.

CONCLUSIONS

FE-LIF, which is safe, effective, and minimally invasive, exhibits the same clinical efficacy as MIS-TLIF but with longer operation time and increased radiation exposure.

Full-Endoscopic versus Minimally Invasive Lumbar Interbody Fusion for Lumbar Degenerative Diseases : A Systematic Review and Meta-Analysis

Objective

Although full-endoscopic lumbar interbody fusion (Endo-LIF) has been tried as the latest alternative technique to minimally invasive transforaminal lumbar interobody fusion (MIS-TLIF) since mid-2010, the evidence is still lacking. We compared the clinical outcome and safety of Endo-LIF to MIS-TLIF for lumbar degenerative disease.

Methods

We systematically searched electronic databases, including PubMed, EMBASE, and Cochrane Library to find literature comparing Endo-LIF to MIS-TLIF. The results retrieved were last updated on December 11, 2020. The perioperative outcome included the operation time, blood loss, complication, and hospital stay. The clinical outcomes included Visual analog scale (VAS) of low back pain and leg pain and Oswestry disability index (ODI), and the radiological outcome included pseudoarthosis rate with 12-month minimum follow-up.

Results

Four retrospective observational studies and one prospective observational study comprising 423 patients (183 Endo-LIF and 241 MIS-TLIF) were included, and the pooled data analysis revealed low heterogeneity between studies in our review. Baseline characteristics including age and sex were not different between the two groups. Operation time was significantly longer in Endo-LIF (mean difference [MD], 23.220 minutes; 95% confidence interval [CI], 10.669–35.771; p=0.001). However, Endo-LIF resulted in less perioperative blood loss (MD, -144.710 mL; 95% CI, 247.941–41.478; p=0.023). Although VAS back pain at final (MD, -0.120; p=0.586), leg pain within 2 weeks (MD, 0.005; p=0.293), VAS leg pain at final (MD, 0.099; p=0.099), ODI at final (MD, 0.141; p=0.093) were not different, VAS back pain within 2 weeks was more favorable in the Endo-LIF (MD, -1.538; 95% CI, -2.044 to -1.032; p<0.001). On the other hand, no statistically significant group difference in complication rate (relative risk [RR], 0.709; p=0.774), hospital stay (MD, -2.399; p=0.151), and pseudoarthrosis rate (RR, 1.284; p=0.736) were found.

Conclusion

Relative to MIS-TLIF, immediate outcomes were favorable in Endo-LIF in terms of blood loss and immediate VAS back pain, although complication rate, mid-term clinical outcomes, and fusion rate were not different. However, the challenges for Endo-LIF include longer operation time which means a difficult learning curve and limited surgical indication which means patient selection bias. Larger-scale, well-designed study with long-term follow-up and randomized controlled trials are needed to confirm and update the results of this systematic review.

Comparison of electromagnetic and optical navigation assisted Endo-TLIF in the treatment of lumbar spondylolisthesis

Uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion (Endo-TLIF) with percutaneous pedicle screw fixation is a promising, minimally invasive method for the treatment of lumbar spondylolisthesis. However, repeated radiation exposure from X-rays and the steep learning curve remain to be improved.

[Comparison of effectiveness between percutaneous coaxial large-channel endoscopic lumbar interbody fusion and minimal invasive transforaminal lumbar interbody fusion in treatment of degenerative lumbar spinal stenosis]

OBJECTIVE

To compare the effectiveness of percutaneous coaxial large-channel endoscopic lumbar interbody fusion (PE-LIF) and minimal invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of degenerative lumbar spinal stenosis.

METHODS

The clinical data of 134 patients with single-segment degenerative lumbar spinal stenosis who met the selection criteria between January 2019 and January 2021 were retrospectively analyzed, including 52 cases in PE-LIF group and 82 cases in MIS-TLIF group. There was no significant difference in general data such as gender, age, disease duration, surgical segment, and preoperative visual analogue scale (VAS) scores of low back pain and lower extremity pain, and Oswestry disability index (ODI) between the two groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospitalization stay, and complications were recorded and compared between the two groups. The level of serum creatine kinase (CK) was recorded at 1 day before operation and at 1 and 3 days after operation to evaluate intraoperative muscle damage. The Brantigan criteria was used to evaluate the interbody fusion in the two groups. The VAS scores of low back pain and lower extremity pain at 1 day before operation and at 3 days, 3 months, and 1 year after operation, and the ODI scores at 1 day before operation and at 3 months and 1 year after operation were recorded and compared between the two groups.

RESULTS

There was no significant difference in operation time and hospitalization stay between the two groups ( P>0.05). The intraoperative blood loss and postoperative drainage in the PE-LIF group were significantly lower than those in the MIS-TLIF group ( P<0.05). There was no significant difference in serum CK between the two groups before operation ( P>0.05), and the serum CK in the PE-LIF group at 1 and 3 days after operation were significantly lower than those in the MIS-TLIF group ( P<0.05). All patients were followed up regularly for 1 year. The postoperative VAS scores of low back pain and lower extremity pain and ODI score in both groups were significantly lower than those before operation ( P<0.05); there was no significant difference between the two groups ( P>0.05). At 1 year after operation, 48 patients in PE-LIF group had successful interbody fusion, and 77 patients in MIS-TLIF group had successful interbody fusion. There was no significant difference in the interbody fusion distribution between the two groups at 3 months and 1 year after operation ( P>0.05). There were 2 and 3 cases of lower limb numbness, 1 and 3 cases of neuroedema pain, 1 and 1 case of Cage displacement, 1 and 1 case of pedicle screw loosening in the PE-LIF group and MIS-TLIF group, respectively. No infection or dural sac tearing occurred in the two groups. There was no significant difference in the incidence of complications between the two groups (9.6% vs. 9.8%) ( χ ²=0.001, P=0.979).

CONCLUSION

In the treatment of single-segment degenerative lumbar spinal stenosis, PE-LIF can achieve similar effectiveness as MIS-TLIF, and PE-LIF has less intraoperative blood loss and less muscle damage.

Unilateral approach with two-cage insertion for full endoscopic transforaminal lumbar interbody fusion: technical report

BACKGROUND

The advantages of performing a transforaminal lumbar interbody fusion (TLIF) with two cages rather than a single cage include a larger cage-bone contact area and higher interbody stability.

METHODS

A customized cage guide is docked in the disc space created after a total facet resection. The first cage is inserted deeply into the contralateral disc space. The second cage is then inserted using the cage guide device while protecting the exiting and traversing nerve roots.

CONCLUSION

We successfully inserted two cages from unilateral side during full endoscopic TLIF. This technique is recommended for L4-L5 and L5-S1 levels.

Percutaneous Bilateral Endoscopic Lumbar Interbody Fusion: Technical Note and Preliminary Results

Objective

The purpose of this study was to investigate the feasibility and clinical efficacy of the percutaneous bilateral endoscopy technique (microendoscopic trans-Kambin's triangle lumbar interbody fusion + percutaneous endoscopic transforaminal decompression of the lumbar spinal canal, ME-TKT-LIF+ PETD) in the treatment of lumbar degenerative diseases.

Methods

From May 2016 to September 2018, 29 patients (16 males and 13 females) who suffered from neurologic symptoms due to degenerative lumbar spine disease and underwent percutaneous bilateral endoscopy technique were enrolled. A microendoscope was used for fusion, and a percutaneous endoscope was used for spinal canal decompression. These patients' perioperative and clinical outcome-related parameters were collected and analyzed.

Results

The mean intraoperative blood loss was 72.8 ± 40.6 ml, the operation time was 87.1 ± 10.1 min, the postoperative ambulatory time was 1.69 ± 1.0 days, the hospital stay was 2.6 ± 1.3 days, and the follow-up period was 22.34 ± 4.2 months. The visual analog scale (VAS) and the Oswestry disability index (ODI) were significantly improved at the early postoperative and last follow-up, respectively. According to the modified MacNab criteria, 11 (11/29) cases were rated as excellent, 15 (15/29) as good, and 3 (3/29) as fair, and the excellent and good rate was 89.7%. Twenty-eight (28/29) cases demonstrated solid fusion, and the fusion rate was 96.6%.

Conclusion

The percutaneous bilateral endoscopy technique is safe and feasible in the treatment of lumbar degenerative diseases, with the advantage that more normal anatomical structures are preserved. It is an optional method of lumbar interbody fusion.

Differential Agnostic Effect Size Analysis of Lumbar Stenosis Surgeries

STUDY DESIGN

A meta-analysis of 89 randomized prospective, prospective, and retrospective studies on spinal endoscopic surgery outcomes.

OBJECTIVE

The study aimed to provide familiar Oswestry Disability Index (ODI), visual analog scale (VAS) back, and VAS leg effect size (ES) data following endoscopic decompression for sciatica-type back and leg pain due to lumbar herniated disc, foraminal, or lateral recess spinal stenosis.

BACKGROUND

Higher-grade objective clinical outcome ES data are more suitable than lower-grade clinical evidence, including cross-sectional retrospective study outcomes or expert opinion to underpin the ongoing debate on whether or not to replace some of the traditional open and with other forms of minimally invasive spinal decompression surgeries such as the endoscopic technique.

METHODS

A systematic search of PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials from 1 January 2000 to 31 December 2019 identified 89 eligible studies on lumbar endoscopic decompression surgery enrolling 23,290 patient samples using the ODI and VAS for back and leg pain used for the ES calculation.

RESULTS

There was an overall mean overall reduction of ODI of 46.25 (SD 6.10), VAS back decrease of 3.29 (SD 0.65), and VAS leg reduction of 5.77 (SD 0.66), respectively. Reference tables of familiar ODI, VAS back, and VAS leg show no significant impact of study design, follow-up, or patients' age on ES observed with these outcome instruments. There was no correlation of ES with long-term follow-up (P = 0.091). Spinal endoscopy produced an overall ODI ES of 0.92 extrapolated from 81 studies totaling 12,710 patient samples. Provided study comparisons to tubular retractor microdiscectomy and open laminectomy showed an ODI ES of 0.9 (2895 patients pooled from 16 studies) and 0.93 (1188 patients pooled from 5 studies). The corresponding VAS leg ES were 0.92 (12,631 endoscopy patients pooled from 81 studies), 0.92 (2348 microdiscectomy patients pooled from 15 studies), and 0.89 (1188 open laminectomy patients pooled from 5 studies).

CONCLUSION

Successful clinical outcomes can be achieved with various lumbar surgeries. ESs with endoscopic spinal surgery are on par with those found with open laminectomy and microsurgical decompression.

CLINICAL RELEVANCE

This article is a meta-analysis on the benefit overlap between lumbar endoscopy, microsurgical decompression, laminectomy, and lumbar decompression fusion.

LEVEL OF EVIDENCE: 2

Comparative Clinical and Radiographic Cohort Study: Uniportal Thoracic Endoscopic Laminotomy With Bilateral Decompression by Using the 1-Block Resection Technique and Thoracic Open Laminotomy With Bilateral Decompression for Thoracic Ossified Ligamentum Flavum

BACKGROUND

Symptomatic thoracic myelopathy secondary to thoracic ossified ligamentum flavum (OLF) often requires decompression spinal surgery.

OBJECTIVE

To compare clinical and radiological outcomes in uniportal endoscopic vs open thoracic decompression for thoracic OLF.

METHODS

Retrospective evaluation of patients who underwent uniportal thoracic endoscopic unilateral laminotomy with bilateral decompression (TE-ULBD) by using the one-block resection technique compared with thoracic open laminotomy (TOL) with bilateral decompression. Radiological outcomes in MRI scan and clinical charts were evaluated.

RESULTS

Thirty-five levels of TE-ULBD were compared with 24 levels of TOL. The overall complication rate of TOL was 15% while TE-ULBD was 6.5%. Both TOL and TE-ULBD cohort had significantly improved their visual analog scale (VAS), Oswestry Disability Index, and Japanese Orthopaedic Association (JOA) myelopathy score after operation. Comparative analysis of TE-ULBD performed statistically and significantly better than TOL in improvement of final VAS and JOA scores. The mean difference ± standard deviation of VAS and JOA improvement in final follow-up when compared with preoperative state of TE-ULBD and TOL was 0.717 ± 0.131 and 1.03 ± 0.2, respectively, P < .05. The mean Hirabayashi recovery rates were 94.5% (TE-ULBD) and 56.8% (TOL). There was no statistical difference in change in preoperative and final Oswestry Disability Index and MRI volume at upper endplate, middisk, and lower endplate canal cross-sectional area.

CONCLUSION

Uniportal TE-ULBD achieved significantly improved pain and neurological recovery with sufficient spinal canal decompression, as compared with thoracic open laminectomy for patients with myelopathy secondary to OLF in our cohort.

Remodeling Pattern of Spinal Canal after Full Endoscopic Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: One Year Repetitive MRI and Clinical Follow-Up Evaluation

Objective: There is limited literature on repetitive postoperative MRI and clinical evaluation after Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. Methods: Clinical visual analog scale, Oswestry Disability Index, McNab’s criteria evaluation and MRI evaluation of the axial cut spinal canal area of the upper end plate, mid disc and lower end plate were performed for patients who underwent single-level Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. From the evaluation of the axial cut MRI, four types of patterns of remodeling were identified: type A: continuous expanded spinal canal, type B: restenosis with delayed expansion, type C: progressive expansion and type D: restenosis. Result: A total of 126 patients with single-level Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression were recruited with a minimum follow-up of 26 months. Thirty-six type A, fifty type B, thirty type C and ten type D patterns of spinal canal remodeling were observed. All four types of patterns of remodeling had statistically significant improvement in VAS at final follow-up compared to the preoperative state with type A (5.59 ± 1.58), B (5.58 ± 1.71), C (5.58 ± 1.71) and D (5.27 ± 1.68), p < 0.05. ODI was significantly improved at final follow-up with type A (49.19 ± 10.51), B (50.00 ± 11.29), C (45.60 ± 10.58) and D (45.60 ± 10.58), p < 0.05. A significant MRI axial cut increment of the spinal canal area was found at the upper endplate at postoperative day one and one year with type A (39.16 ± 22.73; 28.00 ± 42.57) mm2, B (47.42 ± 18.77; 42.38 ± 19.29) mm2, C (51.45 ± 18.16; 49.49 ± 18.41) mm2 and D (49.10 ± 23.05; 38.18 ± 18.94) mm2, respectively, p < 0.05. Similar significant increment was found at the mid-disc at postoperative day one, 6 months and one year with type A (55.16 ± 27.51; 37.23 ± 25.88; 44.86 ± 25.73) mm2, B (72.83 ± 23.87; 49.79 ± 21.93; 62.94 ± 24.43) mm2, C (66.85 ± 34.48; 54.92 ± 30.70; 64.33 ± 31.82) mm2 and D (71.65 ± 16.87; 41.55 ± 12.92; 49.83 ± 13.31) mm2 and the lower endplate at postoperative day one and one year with type A (49.89 ± 34.50; 41.04 ± 28.56) mm2, B (63.63 ± 23.70; 54.72 ± 24.29) mm2, C (58.50 ± 24.27; 55.32 ± 22.49) mm2 and D (81.43 ± 16.81; 58.40 ± 18.05) mm2 at postoperative day one and one year, respectively, p < 0.05. Conclusions: After full endoscopic lumbar decompression, despite achieving sufficient decompression immediately postoperatively, varying severity of asymptomatic restenosis was found in postoperative six months MRI without clinical significance. Further remodeling with a varying degree of increment of the spinal canal area occurs at postoperative one year with overall good clinical outcomes.

Full-Endoscopic Posterior Lumbar Interbody Fusion with Epidural Anesthesia: Technical Note and Initial Clinical Experience with One-Year Follow-Up

Objective

The purpose of this study was to introduce and evaluate the early clinical outcomes of the full-endoscopic posterior lumbar interbody fusion (Endo-PLIF) technique with epidural anesthesia (EA) for single-segment lumbar degenerative diseases.

Methods

In this retrospective case series study, we explored the feasibility and effectiveness of the Endo-PLIF with EA for single-segment lumbar degenerative diseases. Between March 2018 and January 2019, a series of 24 patients with single-segment lumbar degenerative diseases underwent Endo-PLIF surgery and were followed up for a minimum of 12 months (15.21±2.27 months). Clinical outcomes including visual analog scale (VAS) scores for back and leg pain, Oswestry Disability Index (ODI) scores, and the Short Form-36 health survey questionnaire (SF-36) were evaluated preoperatively, and postoperatively at 3 days and at 3, 6, and 12-months.

Results

All patients underwent successful single-segment Endo-PLIF surgery. The mean operation time was 209.17±39.49 min, and average amount of bleeding was 43.33±14.87 mL. The VAS for lower extremity pain and back pain significantly improved at 3 days, and at 3, 6, 12 months compared with preoperative, respectively. The ODI scores decreased from 42.04±3.96 to 12.75±2.71 (P<0.001) at preoperative and 12 months postoperatively, respectively. The SF-36 Physical Component Scores (PCS) improved from 34.96±4.63 preoperatively to 52.08±6.05 (P<0.001) at 12 months postoperatively. Additionally, the SF-36 Mental Component Scores (MCS) improved from 39.38±5.70 at preoperative to 53.13±5.97 (P<0.001) at 12 months postoperatively. Two patients experienced dysesthesia, and one patient had a wound infection.

Conclusion

Endo-PLIF with EA is a feasible and valuable technique for the treatment of single-segment lumbar degenerative diseases in selected patients.

A Narrative Review of Uniportal Endoscopic Lumbar Interbody Fusion: Comparison of Uniportal Facet-Preserving Trans-Kambin Endoscopic Fusion and Uniportal Facet-Sacrificing Posterolateral Transforaminal Lumbar Interbody Fusion

Uniportal endoscopic lumbar interbody fusion aims to achieve the bony union of 2 lumbar segments through cage insertion using full spinal endoscopy. Endoscopic fusion can adjust foraminal height and disc height, improve alignment, and minimize collateral soft tissue damage during the insertion of an interbody cage. The surgery is performed under constant irrigation with normal saline and an optical endoscopic lens close to the targeted disc segment. Two main subtypes of uniportal endoscopic fusion are currently described in the literature. We broadly classify them into facet-preserving and facet-sacrificing endoscopic lumbar interbody fusions. We have termed them uniportal facet-preserving trans-Kambin endoscopic fusion and uniportal facet-sacrificing posterolateral transforaminal lumbar interbody fusion. In this article, we review the current literature and discuss the history, indications, contraindications, technical differences, clinical outcomes, and complications of uniportal endoscopic interbody fusion surgery.

Evaluation of Two Methods (Inside-Out/Outside-In) Inferior Articular Process Resection for Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion: Technical Note

Objective: There is limited literature comparing the uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion outside-in approach (ETLIF (O)) with the inside-out approach (ETLIF (I)). Methods: Radiological evaluation was performed on disc height restoration and coronal wedging angle, and operation time (inferior articular process resection time/total operation time) and clinical evaluation were made. Result: 48 cases of inside-out and 38 cases of outside-in cases were included. Compared to inside-out, the outside-in approach had significantly less operative time required to resect inferior articular process: 36.55 ± 10.37, and total operative time: 87.45 ± 20.14 min compared to 49.83 ± 23.97 and 102.56 ± 36.53 min, respectively, for the inside-out approach, p < 0.05. Compared to the preoperative state, both cohorts achieved significant improvement of VAS and ODI at post-operative 1 week, 3 months and at final follow up. Both cohorts achieved statistically significant increased disc height with 5.00 ± 2.87 mm, 5.49 ± 2.33 mm and statistically significant improvement in coronal wedge angle with 1.76 ± 1.63°, 3.24 ± 2.92° in the inside-out and outside-in approaches respectively. Conclusions: Complete removal of inferior articular process is the key part of endoscopic fusion with two methods that can be applied: an inside-out approach or an outside-in approach. Comparing both techniques, the outside-in approach has a shorter operative time required for inferior articular process resection and total length of operation with similar good clinical and radiological outcomes.

The technical feasibility and preliminary results of minimally invasive endoscopic-TLIF based on electromagnetic navigation: a case series

Background

Uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion (Endo-TLIF) with percutaneous pedicle screw fixation is a promising, minimally invasive method for the treatment of lumbar spondylolisthesis. However, repeated radiation exposure from X-rays and the steep learning curve remain to be improved.

Methods

This retrospective study explored the effects of electromagnetic navigation on improving Endo-TLIF with percutaneous pedicle screw fixation. Clinical information from 42 patients who had received Endo-TLIF with percutaneous pedicle screw fixation from May 2019 to November 2020 was analyzed retrospectively. The procedures were assisted under electromagnetic navigation. The rate of adjustment for guide wires, frequency of X-ray exposure, operative time, accuracy of pedicle screw location, and clinical outcomes were recorded.

Results

The mean follow-up for 42 patients was 11.9 ± 3.1 months. The mean age of the patients was 56.1 ± 9.26 years, with a female/male ratio of 25:17. According to postoperative CT scans and 3D reconstructions, the excellent and good rate of pedicle screws was 96.4%. The rate of adjustment for guide wires under the assistance of electromagnetic navigation was 1.78%, and the frequency of X-ray exposure was 8.27 ± 1.83. The operative time was 167.25 ± 28.16 min, including the duration of guide wire insertion (14.63 ± 5.45 min) and duration of decompression and cage placement (75.43 ± 13.97 min). The duration of hospitalization after operation was 2.59 ± 1.16 days. The preoperative VAS score was 7.51 ± 1.91, and the preoperative ODI was 82.42 ± 8.7%. At the last follow-up, the VAS score was 2.09 ± 0.59, and the ODI was 11.09 ± 3.2%. There were statistically significant improvements in the VAS score and ODI in all patients at the follow-up (p < 0.05).

Conclusions

Electromagnetic navigation can provide accurate positioning and guidance in real time, which improves the surgical efficiency of percutaneous pedicle screw placement and endoscopic decompression in Endo-TLIF with reduced radiation exposures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01148-9.

Clinical Results and Complications of Endoscopic Lumbar Interbody Fusion for Lumbar Degenerative Disease: A Meta-Analysis

BACKGROUND

Although endoscopic transforaminal lumbar interbody fusion (TLIF) may combine the advantages of minimally invasive fusion and endoscopic spine surgery, little evidence exists on endoscopic TLIF. This meta-analysis investigated the clinical results of endoscopic TLIF.

METHODS

We performed a systematic search of Web-based electronic databases to identify articles on endoscopic lumbar interbody fusion. Only studies of water-based endoscopic TLIF with pedicle screw fixation were included. We analyzed preoperative and postoperative scores for the Oswestry Disability Index (ODI) and visual analog scales (VASs) for back and leg pain to evaluate clinical efficacy. The minimal clinically important difference (MCID) of VAS and ODI was analyzed. We calculated differences in means and 95% confidence intervals and investigated indications for endoscopic TLIF, surgical approaches for endoscopic TLIF, the endoscopic systems that were used, and procedure-related complications.

RESULTS

Thirteen articles were included in this meta-analysis. Uniportal and biportal endoscopic systems were used. Six articles used the posterolateral approach and 7 used the trans-Kambin approach. Preoperative ODI and VAS scores for leg and back pain significantly improved after endoscopic TLIF with percutaneous pedicle screw fixation (P = 0.00). The ODI significantly improved by twice as much as the MCID. The mean change in the VAS for back and leg pain showed significant improvements over the MCID. The perioperative complications were usually minor.

CONCLUSIONS

The early clinical results of endoscopic TLIF with percutaneous pedicle screw fixation are favorable. However, long-term outcomes should be investigated and randomized controlled trials should be conducted.

The Evolution of Transforaminal Endoscopic Spine Surgery

Transforaminal endoscopic spine surgery (T-ESS) has become a well-accepted technique. The first attempts at percutaneous discectomy by Kambin and Hijikata opened a new chapter of endoscopic spine surgery. By the last quarter of the twentieth century, spine surgeons had begun to adopt this novel technique. Many researchers helped advance endoscopic spine surgery, but the turning point was the description of a safe transforaminal triangle of safety by Parviz Kambin. Since then, the indications for T-ESS have increased as a result of the description of different surgical approaches such as inside-out, outside-in, and half-and-half. We present a review of crucial historical advancements in T-ESS and also discuss the evolution of endoscopes, the techniques used, development of endoscopic instruments and equipment, transforaminal thoracic endoscopy, transforaminal endoscopic interbody fusions, the growth of extended indications, and the future direction of T-ESS. This review provides a detailed description of key historical moments and a bird's-eye view of the vast scope of T-ESS.

A Narrative Review of Development of Full-Endoscopic Lumbar Spine Surgery

In the first phase of development of lumbar endoscopic spine surgery, the focus was on removal of soft disc material through the working corridor of Kambin’s triangle using transforaminal endoscopic lumbar discectomy. With the introduction of the interlaminar approach and increased interest from both industry and surgeons, there has been an exponential development of endoscopic surgical equipment and a corresponding expansion of endoscopic techniques. Endoscopic treatment strategies are applied to conditions ranging from contained prolapsed intervertebral discs to noncontained migrated herniated discs, hard calcified discs, spinal stenosis in the central or lateral recess and the foraminal and extraforaminal region, and other combinations of degenerative conditions requiring decompression or fusion surgery. The further expansion of endoscopic surgical management involving complicated spinal cases and the final quartet of trauma, infections, tumors, and possibly deformities could be the future stage of endoscopic spine surgery development. This article covers the full range of current treatment strategies and presents possible future developments of endoscopic spine surgery for the management of lumbar spinal conditions.

Technical Considerations of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion: A Review of Its Early Clinical Results in Application in Adult Degenerative Scoliosis

BACKGROUND

Uniportal endoscopic posterolateral lumbar interbody fusion (Endo-TLIF) provides one of the least invasive forms of minimally invasive surgery, allowing large size cages which are commercially available for open and tubular microscopic transforaminal lumbar interbody fusion (TLIF) to be inserted through this approach. We studied the effect of such a technique on a series of patients with low-grade degenerative scoliosis.

METHODS

Endo-TLIF was applied to patients who had 10°-40° of degenerative adult scoliosis. Pre- and postoperative 1-week, 3-month, and final follow-up clinical status of visual analog scale, Oswestry Disability Index, perioperative complications, and Macnab criteria were collected. Roentgenogram to assess changes in Cobb angles was done.

RESULTS

There was statistically significant improvement of preoperative, 1-week postoperative, 3-month postoperative, and final follow-up mean of visual analog scale scores with 7.72 (5-10), 3.68 (3-6), 2.88 (2-4), and 1.96 (1-3), respectively, and with Oswestry Disability Index mean of 70.4 (52-86), 35.12 (26-56), 27.68 (24-38), and 24 (20-28), respectively (P < 0.05). In terms of Macnab criteria, 100% had good to excellent result. In terms of scoliosis measured by Cobb angle, there was statistically significant improvement.

CONCLUSIONS

Endo-TLIF is a safe and effective procedure in mild to moderate degenerative scoliosis with good early clinical results and improvement in coronal Cobb angle. It can be considered as an option if a short segment(s) fusion is planned for adult degenerative scoliosis.